This invention relates to an arrangement for effecting photoirradiation and to a method of photoirradiation for the activation of chemical substances.
It is known that selective drugs such as hematoporphyrin derivative (HPD) when administered to the animal body firstly can be selectively retained in tumours and cancerous tissue and can by effective photoirradiation be made to effect by means which are not yet totally clear, an affect which has a deleterious effect upon the tumour or cancerous tissues.
It is to be realised that while hematoporphyrin derivative is referred to in this specification it is in fact a mixture of compounds and the use of this invention may extend to particular photosensitive elements included within the compound referred to as hematoporphyrin derivative.
Similarly it can extend to other chemical compounds having a similar deleterious effect on tumours or cancerous tissue.
This invention accordingly relates firstly to a method effecting a more effective activation for this purpose of a drug of this type or the invention relates to the apparatus incorporating the particular parts and characteristics necessary to make the discovery effective or the invention relates to the treatment of the human body or the invention relates to the treatment of any animal body.
Thus far, there has been experienced difficulties in providing irradiation of a selected location with sufficient intensity to ensure sufficient activation of the chemical to effect a sufficient action to have the desired effect on the tumour or cancerous tissue without the irradiation itself unduly affecting by heating or otherwise the surrounding flesh.
In the considerable research that has been thus far conducted, there has been difficulty in achieving a sufficiently high irradiation by using a conventional source of radiation without causing this undue damage elsewhere.